1. Field of the Invention
The present invention relates to a protective coating for protecting components of a gas turbine engine or such from wear and a metal structure having wear resistance.
2. Description of the Related Art
A gas turbine engine carries out high-speed revolution under high temperatures and its components rub against opposite components. To protect the respective components from wear, protective coatings are in general formed on limited sites which are subject to wear. The protective coating is made of porous metal and fine pores thereof are impregnated with lubrication oil. Japanese Patent Application Laid-open No. 2002-106301 discloses a related art.
The gas turbine engine is used in a very broad temperature range. During a shutdown, it may go down to minus 50 degrees C. In such an environment, the lubrication oil tends to be solidified. On the other hand, during operation, it may reach up to 250 degrees C., at which the lubrication oil could evaporate. Either case would give rise to a problem with lubrication.